Spurs
Spurs are artificial training aids like whips and crops, designed as a back up to the natural processes of controlling your horse with your seat, legs, hands and voice.
Spurs come in various designs and materials, all designed to amplify the cues you give your horse while riding with your legs as to whether he should proceed, turn or so on. Modern spur styles, such as ball ended, roller and Prince of Wales, are intended to apply gentle encouragement rather than potentially injurious jabs. You can get various dressage spurs and straps according to designs and materials.